用于Buck变换器的开关电流型误差放大器  

A Switched Current Error Amplifier Applied in Buck Converter

作　　者：易子皓 甄少伟[1] 罗攀 方舟 程雨凡 罗萍[1] 张波[1] YI Zihao;ZHEN Shaowei;LUO Pan;FANG Zhou;CHENG Yufan;LUO Ping;ZHANG Bo(State Key Lab.of Elec.Thin Films and Integr.Dev.,Univ.of Elec.Sci.and Technol.of China,Chengdu 610054,P.R.China)

机构地区：[1]电子科技大学电子薄膜与集成器件国家重点实验室,成都610054

出　　处：《微电子学》2021年第6期849-853,共5页Microelectronics

基　　金：“十三五”装备预先研究项目(31513030209)。

摘　　要：提出了一种用于Buck变换器的开关电流型误差放大器(SC-EA)。在Buck结构中,无需片外补偿即可使系统保持稳定,节省了芯片面积,功率密度更高。误差放大器的带宽随开关频率改变而自适应变化,在高频时仍具有较好稳定性和瞬态响应速度。使用开关电流型误差放大器的谷值电流模COT结构实现了片上频率补偿,省掉了片外元件,可实现多路并联均流,具有较快的瞬态响应速度。采用0.18μm BCD工艺进行了电路设计。仿真结果表明,在6 MHz、1 MHz开关频率下,选用10μF、70μF输出电容即可达到环路稳定,实现自适应带宽。在6 MHz开关频率下,上、下阶跃瞬态响应时间分别为6.3μs、5.5μs;在1 MHz开关频率下,上、下阶跃瞬态响应时间分别为27.7μs、28.4μs。A switched current error amplifier(SC-EA)was proposed for the use of buck converters.In the buck structure,the system could be kept stable without off-chip compensation,saving chip area and obtaining higher power density.The bandwidth of the error amplifier adaptively changed with the switching frequency,and it still had good stability and fast transient response speed at high frequency.The on-chip frequency compensation was realized by using the valley current mode COT structure of the switching current mode error amplifier,and the off-chip components were omitted.The multi-channel parallel current sharing was realized,and the transient response speed was faster.The circuit was designed in a 0.18μm BCD process.The simulation results showed that the loop stability and adaptive bandwidth could be achieved by selecting 10μF and 70μF output capacitors at 6 MHz and 1 MHz switching frequency,respectively.At the switching frequency of 6 MHz,the upper and lower step transient response time was 6.3μs and 5.5μs,respectively.At the switching frequency of 1 MHz,the upper and lower step transient response time was 27.7μs and 28.4μs,respectively.

关 键 词：谷值电流模COT控制 BUCK变换器 开关电流型误差放大器 

分 类 号：TN722[电子电信—电路与系统]